Snack foods are a typical American part of any break from school and a holiday staple. There are so many from which to choose, each with its own unique flavor and texture.
In recent years, these well preserved (or petrified) treats have come under near constant criticism from a variety of health professionals. There is concern about the effects of high levels of sugar, salt and trans-fats in the diet along with the absence of nutrients and soluble fiber.
Adults are susceptible to the hazards of these securely packaged menu alternatives, but the major concern is the long-term effects on youth. While some of the human residents of panhandle Florida fret over this topic, one native insect species has no such worries.
Dirt daubers, in the Sphecidae insect family, spend summers busily building nests, usually on protected parts of buildings and other human structures. As with all wasp species, the objective is to raise the next generation.
The nest of a black and yellow mud dauber, Sceliphron caementarium, holds a collection of spiders for the larvae, including a golden orb weaver on top.
Unlike yellow jackets and ground wasps, this is not a social insect which will assemble in large colonies. Though not particularly aggressive, it is capable of delivering a painful sting if provoked.
As an adult, it survives on drinking nectar. Like all wasps however, its larvae are carnivores and must consume the tissue of other insects.
This stage of life is where this genus’ behavior truly distinguishes it from other wasps. It also justly earns its common name.
The females use local soil to construct nests in which to lay their eggs. Using moisture and their mandibles, they construct single egg chambers.
There are two forms commonly encountered. One can be shaped like a pipe organ’s flutes or tubes, the other just an oval glob of dirt.
Nests are sometimes multi-colored. This variation reflects differences in soil types available for the individual nest constructions.
If in shielded sites, the hardened nest can last for years or decades. Once abandoned by the dirt daubers, the nest can be used by other insects for bringing up their young or as homes.
Once built, the females begin a provisioning process to assure the survival of their young. Spiders are the primary food source for the larval hatchlings.
Depending of the dirt dauber species, there are specific native spiders which are targeted to be on the young’s future menu. It is the female dirt dauber’s responsibility to protect the nutrient supplies from drying out and spoilage.
To overcome this challenge, she uses her stinger to immobilize but not kill any unlucky spider. In this state of suspended animation, the comatose spider is alive and a viable food source.
Unable to resist the dirt dauber, the spider is crammed into the egg compartment with others which fall prey to this winged predator. A single leathery egg is deposited in the cavity before it is sealed shut.
In the weeks following the egg’s deposit, it hatches and the larva is able to snack at leisure on the helpless spiders. When strong enough, the new dirt dauber bores out of the nest encasement to begin the process again.
While not likely to be found on the shelves of convenience stores, hapless spiders await their fate under countless eaves and on exterior walls as well-preserved, healthy snacks for future generations of dirt daubers.
While a nutritious choice for dirt daubers, the inanimate spiders will probably never be as popular a snack as potato chips.
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